1. Field of the Invention
This invention relates to vehicle wheel differentials and, in particular, to a brake assembly for use with the differential.
2. Disclosure of the Related Art
A conventional drive axle assembly for driving one or more wheels on opposite sides of a vehicle includes a drive axle comprised of two axle half shafts. The axle assembly further includes a differential that drives the axle half shafts and enables the shafts to rotate at different speeds. The axle assembly further includes two separate braking devices used to brake the wheel or wheels driven by the respective axle half shafts.
The use of multiple braking devices to brake the driven wheels has several disadvantages. For example, the use of multiple braking devices requires additional parts and materials and increases assembly time-all of which increase the cost of the drive axle assembly. The use of multiple braking devices also increases the size and weight of the drive axle assembly.
U.S. Pat. No. 3,994,375 illustrates the use of a single brake assembly for use in braking the wheels on both sides of the drive axle. The disclosed brake assembly, however, still requires the use of multiple actuators and significantly increases the size of the axle and differential housings thereby creating potential interference with other vehicle components.
There is thus a need for a brake assembly that will minimize or eliminate one or more of the above-mentioned deficiencies.
The present invention provides a brake assembly for a drive axle.
A brake assembly for a drive axle in accordance with the present invention includes a brake housing. The brake housing may be coupled to a differential carrier that is disposed about a first axis and the brake housing may include a first portion extending radially and a second portion extending axially from the first portion. The brake assembly also includes a differential hub that is coupled to the differential carrier and is axially movable relative to the differential carrier and the brake housing. The brake assembly further includes first and second friction plate assemblies. The first friction plate assembly is disposed on a first side of the differential hub between the differential hub and the brake housing and is axially movable relative to the differential carrier and the brake housing. The second friction plate assembly is disposed on a second side of the differential hub and is also axially movable relative to the differential carrier. Finally, the brake assembly includes a piston that selectively urges the second friction plate assembly, the differential hub, and the first friction plate assembly in a first axial direction against the brake housing. The inventive brake assembly both provides locking capacity to the differential, thereby preventing or limiting the two axle half shafts of the drive axle from rotation at different speeds, and provides braking capacity to the axle half shafts for stopping the vehicle.
A brake assembly in accordance with the present invention represents a significant improvement as compared to conventional drive axle brake assemblies. In particular, the use of a single brake assembly to brake the driven wheels reduces the number of parts and materials required as compared to conventional drive axle assemblies and decreases assembly time thereby reducing the cost of the drive axle assembly. The use of a single brake assembly also decreases the size and weight of the drive axle assembly relative to conventional drive axle assemblies.
These and other features and objects of this invention will become apparent to one skilled in the art from the following detailed description and the accompanying drawings illustrating features of this invention by way of example.